Arterial biology for the investigation of the treatment effects of reducing cholesterol (ARBITER) 2 - A double-blind, placebo-controlled study of extended-release niacin on atherosclerosis progression in secondary prevention patients treated with statins

Background - Niacin reduces coronary heart disease morbidity and mortality when taken either alone or in combination with statins; however, the incremental impact of adding niacin to background statin therapy is unknown. Methods and Results - This was a double-blind randomized placebo-controlled study of once-daily extended-release niacin (1000 mg) added to background statin therapy in 167 patients (mean age 67 years) with known coronary heart disease and low levels of high-density lipoprotein cholesterol (HDL-C; < 45 mg/dL). The primary end point was the change in common carotid intima-media thickness (CIMT) after 1 year. Baseline CIMT (0.884 +/- 0.234 mm), low-density lipoprotein cholesterol (89 +/- 20 mg/dL), and HDL-C (40 +/- 7 mg/dL) were comparable in the placebo and niacin groups. Adherence to niacin exceeded 90%, and 149 patients (89.2%) completed the study. HDL-C increased 21% (39 to 47 mg/dL) in the niacin group. After 12 months, mean CIMT increased significantly in the placebo group (0.044 +/- 0.100 mm; P < 0.001) and was unchanged in the niacin group (0.014 +/- 0.104 mm; P = 0.23). Although the overall difference in IMT progression between the niacin and placebo groups was not statistically significant (P = 0.08), niacin significantly reduced the rate of IMT progression in subjects without insulin resistance (P = 0.026). Clinical cardiovascular events occurred in 3 patients treated with niacin (3.8%) and 7 patients treated with placebo (9.6%; P = 0.20). Conclusions - The addition of extended-release niacin to statin therapy slowed the progression of atherosclerosis among individuals with known coronary heart disease and moderately low HDL-C.